Tightness in your calves, hamstrings and buttocks can hurt your golf game by leading to a straight and upright posture
Like the other swing in golf, putting is played to the side of the target line so getting the correct posture is key to allowing the putter to travel on a slight arc like every other swing
Distance control is by far the most important part of putting and this practice drill is a fun way to improve by trying to hit successive balls closer to the hole without going past it